Internal-combustion motor



G. A. METCALF. INTERNAL COMBUSTION MOTOR.

APPLICATION FILED SEPT. 23, 1918.

2 SHEETS-SHEET I- Patented Oct. 12, 1920.

G. A METCALF. INTERNAL comsusnou MOTOR.-

APPLICAII'ION HLED SEPT- 23, I918- Patented Oct. 12, 1920.

2 SHEETS-SHEET 2.

//\/ VEN TUE:

UNITED STATES PATENT OFFICE.

GEORGE A. METCALF, 0F MALDEN, MASSACHUSETTS.

INTERNAL-COMBUSTION MOTOR.

Application filed September 23, 1918.

T 0 all whom it may concern Be it known thatI, GEORGE A. METCALF, acitizen of the United States, residing at Malden, in the county ofMiddlesex and State of Massachusetts, have invented new anduseful-Improvements in Internal-Combustion Motors, of which thefollowing is a specification.

This invention has for its object to provide a compact internalcombustion motor having a large. number of cylinders arranged in thesmallest possible space, whereby to enable large powers to be developedin an eflicient manner without requiring a bulky power plant. On thisaccount the invention is particularly adapted to furnish motive powerfor flying machines. A further object is to provide a motor having thecharacteristics above outlined and adapt.-

ed to be used with particular advantage with an upright main shaft.Other objects having to do with a novel compounded power transmissionmeans, with controlling means for admission and exhaust. valves of theseveral cylinders of the motor; with cooling; with lubrication, and withfeatures of construction and arran ement, appear from the followingdetailed escription of a particular embodiment of the invention which Ihave chosen to illustrate and describe herein for the purpose ofillustrating the invention.

The invention consists in the means, instrumentalties and arrangementsfor accomplishing the above stated objects, and in the principlesembodied in the same, as pointed out in the appended claim.

Referring to the drawings, Figure 1 is a vertical sectional view of apractical form or embodiment of the invention.- Fig. 2 is in part a planand in. part a horizontal section of the motor thus shown. Fig. 3 is ahorizontal section on line 3-3 of Fig. 1 showing in plan the parts belowsuch line. Fig. 4 is a section on line 4.-4: of Fig. 1.

Figs. 5 and 6 are elevations of the external valve mechanism. Fig. 7 isa horizontal section through the tappets of said mechanism. Fig. 8 is aplan view of said mechanism.

Like reference characters designate the same parts in all the figures.

Referring to the drawings, 11 represents the main shaft of the motor onwhich is formed a crank consisting of the arms 12, 13 and pin 14,preferably made integral with the shaft, although they may be ofseparate Specification of Letters Patent.

Patented Oct. 12, 1920.

Serial No. 255,230.

parts assembled together if desired. The foot portion 11 is mounted in astep bearmg 15 in which there is a lining bushing 16, such step bearingbeing mounted upon or formed integral with a crank case 17, which ismade in the form of a cup having rising sides 18 which surround thecrank and the parts associated therewith presently to be described.

On the'case l7 thereis mounteda plate or frame 19 which forms a. coverfor the space inclosed within the case, and also a support for thecylinders of the motor. Said plate or frame may be mounted in anydesired way upon the'case, and is here shown as being .set within therim of the side wall 8 resting upon a ledge 20 therein, to which it. issecured by bolts or in any other desired fashion.

Upon the plate 19 are mounted a number of cylinders 21, the latter beingarranged with their axes parallel to the shaft 11 and in a seriessurrounding said shaft, all the cylinders being equally distanttherefrom and preferably equally spaced apart from one another.Preferably the cylinders are placed as close together as they can bearranged and at the same time leave openings between them wide enoughfor flow therefrom of such volume of air as may be necessary to coolthem. The bases or crank ends of these cylinders rest upon plate 19 andare provided with lugs or flanges 22 for connecting them with holdingbolts. Preferably the lugs or flanges on each cylinder meet the adjacentlugs or flanges of the next cylinder, and each of these flangesisrecessed to register with recesses in the contiguous flanges, theregistering recesses together forming openings throu h which holdingbolts 23, 24 are passed. T he upper ends of said bolts are threaded andupon them are screwed holding nuts 25, 26 which bear upon the beforementioned flanges, each bearing on parts of the flanges of two adjacentcylinders. The lower ends of these bolts pass through the bottom of thecrank case and carry nuts 27 28 which underlie the bearing shouldersformed on the under side of the crank case. Thereby the cylinders arefirmly secured in the case and by the minimum number of holding means,since each of the holding bolts thus partly secures two cylinders.

I prefer to make the motor of such di mensions as to the individualcylinders and as to the radial distance thereof from the shaft, toaccommodate an odd number of cylinders, preferably fifteen; although 1do not limit the invention either to this specific number of cylindersor even to a motor having an odd number rather than an even number ofcylinders.

In each cylinder is a reciprocating piston 29 having a wrist pin 30 bywhich is pivoted thereto a connecting rod 31. Said rod extends into thecrank case and is connected by a knuckle pin 32 with a link 33 pivdtallymounted on an abutment pin- 34 which is supported by the crank case in afixed location but in a manner permitting'it to turn about an axisparallel to the shaft and approximately in line with the axis of thecylinder. A convenient means for thus mounting said abutment pincomprises a cylindrical block 35 (Fig. 1) having a bearing for the pin34 and mounted in a bushing. 36 placed in a socket 37 which is securedto the crankcase preferably by the bolts and nuts 27, 28, and opens intothe interior of the latter. The block 35 is adapted to turn in thebearing thus formed in order that the linkage above described mayoscillate conformably to the movements of the crank 14. Power isdelivered from the knuckle 32 to said crank through a link or connectingrod 38 which is pivoted to the knuckle 32 and also to a second knuckle39 which is carried by a pin 40 having its bearing in a crank disk 41.Said disk embraces the crank pin and provides a bearing for the latter,being lined with a bushing 42. Preferably this crank disk ismade in twoparts which fit together about the crank pin and are secured together bybolts 43. All of the cylinders of the motor are thus connected to thesame disk 41 by linkages and connecting rods iden ticalwith that justdescribed. Thereby as each piston travels toward the crank case in itsworking stroke, it moves the knuckle 32 with which it is respectivelyconnected toward the crank, and through the link 38and disk 41 appliesforce to the crank. The cylinders successively apply such pressureimpulses in this manner to the one crank. It is to be understood, ofcourse, that the cover or base plate 19 is provided with openingsbeneath the several cylinders of proper form and dimensions to permitunobstructed movement of the rod 31 both toward the shaft and alsooscillatively about the axis of the crank pin. This means comprises oneor more auxiliary cranks 44, there being preferably three such cranksinorder to distribute the guiding effect uniformly and prevent crampingof the disk. So far as the principle of the invention is concerned,there may be fewer or more of these guiding cranks; burt I prefer to usethree of them rather than any other number in order both to secure equaldistribution of the effect and also to avoid unnecessary weight whichwould be occasioned by providing more than three of them. Each of thesecranks is mounted on a stud shaft 45 which turns in a bearing 46 fixedlymounted upon the bottom of the crank case; these crank arms are e ual inlength to the arm of crank14, and t ey are connected to the disk 41either by being engaged with one of the wrist pins 40 previouslydescribed, or with other 'pins similarly mounted in the disk 41. Ofcourse the guiding cranks are spaced with approximate equality anduniformity around the axis of the main shaft. Obviously the effect ofthe auxiliary guiding cranks is to cause the disk to revolve about theaxis of the shaft without turning about the crank in. p The points ofconnection of the several driving linkages with the crank disk thusmission o-f power from a cylinder to a shaftparallel to the cylinder Ibelieve to be new and desire to protect broadly. Essentially itcomprises acomposite connecting rod consisting of the links 31 and 38, acrank box, namely the disk 41, and an abutment, the link 33, whichconverts the axial thrust of the piston into a thrust at right anglesthereto. By this means it'is made possible to arrange as many cylindersaround the main shaft as it is physically possible to place in the spaceavailable, and to transmit force from each cylinder to the shaft withthe maximum efiiciency.

I also claim broadly as my invention, and without limitation to itscombination with cylinders parallel to the shaft, the idea of the disk41, or any element substantially equivalent in function and resultthereto, mounted on a crank and connected with the pistons or connectingrods of several cylinders in such manner as to transmit the force ofpressure strokes therefrom to the crank;

that the points of connection thereof with the several connecting rodsdescribe circular paths about different axes. This feature, in the scopein which I claim protection for it, is applicable in ways obvious tothose skilled in the art to plural cylinder motors in which the cylinderaxes are radial to the shaft, or are otherwise located in a plane orplanes other than parallel to the shaft; and when so applied, causes thephases of all the cylinders tobe alike and the power impulses of i theseveral cylinders upon the shaft to be alike and equal. This result isdue to the fact that the point of connection between each connecting rodand the disk is in effeet a crank which may be placed in relation to thecylinder such as to secure the desired effects, and that the line ofthrust through the disk from each such point to the actual crank isequivalent to a transmission rod of which all the ositions are parallelto one another. In this description the term disk is intended to includeall devices adapted to perform the functions and secure the results ofthe disk 41 as here described, and regardless of whether such devicesare flat either within or outside of the circle of cylinders, and isconnected at any suitable point with the air trunk; or I may provide anumber of carbureters, if necessary, to supply a suflicient quantity ofthe mixture for running at maximum power. Any carbureter either thosenow used and well known, or others which may be devised may be providedin connection with this motor; wherefore, and because the presentinvention does not involve any new invention or design in a carbureter,I have simply indicated diagrammatically a carbureter at 48, withoutattempting to show the same in detail. This representation is intendedto show that I contemplate as part of the operative motor combination,adequate means for furnishing combustible working fluid.

The distributing branches 49 lead from the trunk 47 to the head ends ofthe several cylinders, and each is under the control of an inlet valve50. There is also arranged in each cylinder an exhaust valve 51 whichcontrols the entrance to the exhaust passage 52 which discharges intothe outer air, either directly or through any suitable muffler which itmay be desired to use. These valves open inwardly, whereby the internalpressure developed in the cylinder tends to close them, and they arefurther constantly maintained against their seats by springs 53 and 54,such springs bearing against abutments on the stems of the valves andreacting against the housing 55 in which the inlet and exhaust passagesare contained. For opening these valves at proper times to admit freshcharges and to exhaust the expanded charges, I provide valve mechanismsof which that for the inlet valve comprises an arm 56 mounted upon astud 57 and having a tappet 58 which bears on the stem of valve 50. Arm56 is connected to a rod 59 which carries a roll 60 bearing upon a cam61 which is mounted on a tubular shaft 62 surroundin and rotatable uponthe main shaft 11. exhaust valve is similar thereto and comprises an arm63 pivoted upon the stud 57,

a tappet 64 connected to said arm and bearing against the stem of valve51,- a link or connecting rod 65 connected to arm 63, and a cam 66 foractuating said rod. The cams 61 and 66 are rotated at one half the speedof the main shaft by gearing consisting of a spur gear 67 fixed to themain shaft 11, a compound gear 68, 69, ofwhich the part 68 meshes withthe gear 67, and a driven gear in mesh with the gear element 69 andfixed by any suitable means, here shown as by set screws 71, upon thetubular shaft 62. The value of the gear train 67, 68, 69, 70 is such asto turn the shaft 62 at one half the speed of the main shaft since theoperation of the motor is on the four stroke cycle. On account of thetiming problem, I prefer to provide more than one cam of each sort; thatis, instead of operating the inlet valves of all the cylinders by thesame cam 61, and all the exhaust valves by the same cam 66, I provideone or more additional inlet cams 72 and one or more additional exhaustcams 73, each of these cams controlling the valves of only a part of thecylinders. The number of these cams may be indefinitely extended ifdesired, up to the limit where there is a separate cam foreach valve.

Cooling means-This motor is arranged to be air cooled, and for thispurpose there is mounted on the main shaft 11 a fan 74 which drives airagainst the heads of the cylinders and into the space surrounded by thecylinders. In. escaping from this space the air flows through theopenings between the adjacent cylinders and is thereby brought intointimate contact with the cylinder walls. There are also provided on theexterior of the cylinders conducting flanges or fins 75 to aid in theflow of heat from the cylinders to the outgoing air. By this means ampleaeration and cooling of the motor is effected. In addition, when themotor is arranged in upright position and is carried by a rapidly movingflying machine or other vehicle. and is at the same time exposed to theouter air, external air currents have a powerful cooling effect upon theouter sides of the cylinders. Of course, if desired, "a watercoolingsystem constructed and operated according to known principles may be provided in place of the air cooling system described or in combinationwith air cooling.

m'ti0n.-I have designed this motor with an ignition system operating onthe jump-spark principle. In Fig. 1 I have illustrated the outer ends ofspark plugs 76 in two of the cylinders, and have shown in a diagrammaticmanner a source of current in the form of a battery 77, and also in adiagrammatic way, a transformer 78. It is to be understood, however,that a magnetic or other generator may be used instead of the battery asthe source of current. one terminal as 79 of the transformer is shown asbeing grounded on the motor base while the other terminal 80 is joinedby a conductor 81 with a distributer 82, the

' the latter and being latter'having a fixed member bearing separatedcontacts which are connected by wires 83 with the several spark plugs,and a movable member carried by the movable cam shaft 63 and having asingle complemental contact with which the conductor 81 is in connectionthrough any suitable sort of slip contact or brus Lubricatimz-.-Thecrankcase 17 is intended to be kept partly filled with oil. In the crankcase and having its inlet dipping into the body of oil there containedis a pump 84 having admission and exhaust check valves and a plunger 85.One of the guiding crank shafts 45 is formed in part as a cam oreccentric 86, and the pump is so arranged that the plunger is actuatedby said cam, being pushed inward with every rotation of alternatelypushed outward by a spring 8 This pump discharges into a conduit 88which carries oil to any desired point of discharge. It is here shown as)assin throiwh the up er end of the.

l n a P tubular cam shaft 62 and delivering oil so as to lubricate thelatter. This conduit may have as many branches as desired leading to allpoints which require to be continuously lubricated; or there may be anumber of mains leading to such points independently from the pump 84;or a number of such pumps may be provided, all according to therequirements of any specific motor built according to the inventiondescribed. Also oil is distributed by an arm 89 extending laterally fromthe main shaft and having a passage 90 which runs through the crank arm12, crank pin 14, arm 13 and foot 11 of the shaft, through the end ofwhich taining this oil pump in effective condition by preventing backflow of oil from the passage. It will be readily appreciated that thearm 89 is in essence a centrifugal. pump. The discharge orifice of thisarm is near the line of cylinders and it ejects oil into them in turn asit revolves. Thereby the pistons are lubricated; and the oil which dripstherefrom and is splashed by the movement of the reciprocating partslubricates the other rubbing parts in the engine base.

Starting means.I have shown a starting 1 crank 93 mounted on a shaft 94,the bearings for which are provided by a bracket 95fixed to the crankcase and by the post 96 which also supports the reducing gears 68, 69.On this shaft is fixed a beveled pinion 97 meshing with a beveled gear98 fixed upon the main shaft. The pinion is mutilated in part so that itwill not mesh throughout its entire circumference with the gear 98, inorder that when the motor starts to run the shaft 94 will not becontinuously rotated. Between the crank 93 and shaft 94 I may provideany relation of clutch such as are used in connection with automobilestarting cranks. The foregoing describes the essentials of the motor andthe principal structural details. Such other details as are common toall motors, or may be applied thereto by any competent machine designerwithout difficulty are not shown. Among the latter are such details asbrackets or a bed for supporting the motor as a whole and mounting itupon the frame of the flying machine or other vehicle to which it isapplied; the stiffening frame or other supports for holding thecylinders in their proper alinements; guides for the valve operatingrods 59 and 65, etc. Any structural details suitable to serve the lastnamed purposes may be added to the motor by the designer in adapting itto any special use.

To the extent that such details as may be necessary to make astructurally complete motor may be lacking from these drawings, thelatter are to be considered as diagrammatic for the purpose of giving afull, clear and exact description of the principles of' the invention insuch form as to enable those skilled in the art of constructing machinesto apply such principles in a structurally perfect motor.

It will be apparent from what has gone 30 tions consistin to, and byenabling as many cylinders to be thus arranged as it is physicallypossible to vplace withln the line wherein they must be located. Thatis, nothing but the external diameter of the cylinders themselves limitsthe number which can be so placed.

Thus the desired object of high power with small bulk and relativelylight weight is accomplished. This engine 1s adapted to be placed in anupright position, in which 16 the shaft is vertical, and thus to drivethe horizontal fan propellers of a 'fiyin machine such as that shown inmy prior atent No. 908794, dated January 5, 1909. Of course, power maybe transmitted to a hori- 20.zont al or an inclined shaft byintermediate beveled gearing between the same and the main shaft fordriving propellers or other instrumentalities which rotate on horizontalor inclined axes; or the entire motor may be mounted on its side foraeroplane, automob1le or motor boat use.

Advantages residing in the compound linkages or connecting rods betweenthe cylinders and crank, that is, in the combinaof the rods or links 31,33 and 38, to which I desire to call attention are the following: Thelinks 31 and 38 form what is in effect a jointed connecting rod disposedto deliver force in a direction transverse (at right angles, or anyother de-' sired angle) to the line in which the piston reciprocates;and the link 33 is an abutment and guide for the joint in such rod,enabling it to erform this -oflice. Thereby thrusts 40 are de 'veredlaterally of the cylinder with better effect and greater efiiciency thanis i found in other types of motor having cylinders parallel to theshaft. The same mechanism enables a large number of cylinders to becombined in one motor without requiring the disk 41 to be unduly lar e.Also such mechanism is exceedin 1y e cient in propelling the pistonduring its compression stroke, on account of the mechanical advantageresulting from the links 31 and 33 approaching a straight line at thesame time that the I0 38 and the crank come into line. Thereby a higherdegree of compression than can be secured in the ordinary type ofreciprocating engine is attainable with less effort. This feature of theinvention is not necessarily dependent on the disk 41, or equivalent,wherefore my broad claim thereto is not limited to a combinationincluding the disk. And as the same feature is applicable to pumps orcompressors in which one or more compressing pistons is, or .are, drivenby a shaft, I desire to obtain protection for the same in such scope aswill cover 66 the application thereof to pumps or compressors. Hereinthe swivel I or rotatable mounting of the links 31 and 33 is important,as it enables this linkage to swing in following the movements of thecrank.

WhileI have described the cylinders as parallel to the shaft, I do notmean to exclude from the scope of my protection an' arrangement b whichthe cyilnders are more or less inc ined to the shaft without beingperpendicular thereto. The particular connecting rod linkage hereindescribed and claimed is operative when the cylinders are more or lesssteeply inclined to the shaft,

and is desirable in engines having that relation and therefore in theclaim which is directed to this feature particularly, theterm parallelas defining the relation between the cylinders and the shaft is to becon--' strued as including all the combinations in which such or'an euivalent linkage may be used, and in whic the cylinders are arran edotherwise than perpendicular to the sha t. Also the crank may beinclined to a greater or less extent to the axisof the shaft and, thelinkage usedas .before described, the cylinders being then eitherinclined or parallel to the shaft. In that case the disk used totransmit power to the crank will be complementall inclined to the shaft,and it may be withhe d from rotation about its own center by other meansthan the supplemental cranks; such, for example as ears of the sort'shown in Patent No. 790,3 4 of J. W. Maxwell, anted Ma 23, 1905.

Having now escribed t e principles of my invention, but withoutattempting to illustrate all the forms in which it may be embodied orall the ossible modes in which and pu oses for' w ich it ma be used, Ideclare t at what I claim and esire to protect by Letters Patent is Amotor embod 'ng a crank shaft, and cylinders arran e crank shaft wit anaxis parallel thereto, a disk rotatably carried by the crank of said ina series surrounding Y crank shaft, pins equal in number to thecylinders on same disk in a series surroundin the crank,a linka eassociated with each cy inder consisting o a connecting rod attached tothe piston of the cylinder, a second link joined to the connecting rodapproximately at the plane of said disk, a link connecting the jointlast identified with the disk-carried pin nearest thereto, a swiveledabutment substantially in the axis of the cylinder to which the firstidentified link is connected, and a guide crank in parallel with maincrank engaged with said disk to prevent any effective rotation of thedisk about the main crank under the impulse applied by said linkage.

In testimony whereof I have afiixed my signature.

